1. Field of Invention
The invention relates to a fan system and a starting method thereof, and, in particular, to a fan system and a starting method thereof capable of enhancing the stability and the security.
2. Related Art
With the high development of the technology, the requirements on the functions of an electronic apparatus are getting higher and higher, the number of the used electronic elements and the integration are getting higher and higher, and the heat dissipating requirement is also getting higher and higher. Therefore, the heat dissipating function directly influences the reliability and the lifetime of the electronic apparatus.
A fan is frequently used to serve as a heat-dissipating device, and the number of fans is usually increased or decreased according to different requirements of the corresponding clients when being used at a customer system end. In addition, the rotating speed of each fan in the fan system is controlled and driven by a controlling device or a controlling chip so that the rotating speed of the fan may be adjusted according to the actual operating conditions of the customer system.
As shown in FIG. 1, a conventional fan system is electrically connected with a customer system end SB1. The fan system includes a hot-swap controlling device 11, a controlling device 12 and a fan device 13. Usually, the customer system end SB1 provides main power MP1 and sub-power SP1 and includes a connector C1 for transmitting a first driving signal S01 generated by the main power MP1 and a second driving signal S02 generated by the sub-power SP1 to the fan system.
The hot-swap controlling device 11 includes a plurality of hot-swap elements 111 and 112 electrically connected to each other, and a plurality of pins 113. The hot-swap elements 111 and 112 are electrically connected with the customer system end SB1, the controlling device 12 and the fan device 13, and receive the first driving signal S01 and the second driving signal S02, respectively.
The controlling device 12 is a digital signal processor or a microprocessor, and the hot-swap element 112 transmits the second driving signal S02 to start the controlling device 12.
The fan device 13 is electrically connected with the controlling device 12, and includes a plurality of fans 131 and a plurality of isolating circuits 132. The hot-swap elements 111 transmit the first driving signals S01 to start the fans 131, respectively, while the isolating circuits 132 are electrically connected with and between the controlling device 12 and the fans 131 to transmit a pulse width modulation (PWM) signal P generated by the controlling device 12 to the fans 131 so that rotating speeds of the fans 131 are controlled according to the PWM signal P.
In general, the fan system has to provide the sufficient heat dissipating requirement for the customer system end SB1 in any state. When one of the fans 131 of the fan system is damaged, the fan can be immediately replaced in a hot-swap manner through the hot-swap element 111 so that the heat dissipating requirement of the customer system end SB1 is kept. However, the hot-swap elements 111 and 112 correspondingly connected to the main power MP1 and the sub-power SP1 of the customer system end SB1 are powered on independently. When the user improperly swaps the fan, the pins 113 of the hot-swap controlling device 11 tend to be bent, and the problem of the poor contact may rise due to the shrank terminal with the connector C1.
In addition, the motor (not shown) of the fan 131 is the dynamic inductive load, and a high start current is required to start the fan 131 from the stationary state to the stable state. At the moment when the fan system is being started, an inrush current, a spike voltage or a spike noise may be generated between the fan system and the connector C1 of the customer system end SB1, or even a spark phenomenon (i.e., an electric arc) is generated, thereby damaging the customer system end SB1 or the fan system.
In addition, the pins 113 of the hot-swap controlling device 11 are now made into a floating connector, as shown in FIG. 2, or a floating board (not shown) to ensure the pins 113 to contact the connector C1 instantaneously. However, this method still cannot effectively and completely suppress the generation of the spike noise on the pins 113. In addition, when the hot-swap is being performed, the positive or negative spike noise generated by the hot-swap elements 111 tends to damage the small-signal electronic element (not shown) of the fan system through the grounding circuit of the main power MP1 and the pins 113. Thus, the isolating circuits 132 are usually provided for the purpose of protection. In addition, if the hot-swap elements 111 are frequently used, the terminals of the pins 113 tend to have the poor contact due to the oxidation, and the lifetime of each of the hot-swap elements 111 tends to be shortened so that the quality of the fan system is deteriorated.
Therefore, it is an important subject to provide a fan system and a starting method thereof capable of effectively suppressing the generation of an inrush current, a spike voltage or a spike noise when the fan system is started, so that a customer system end and the fan system can be simultaneously protected.